1. Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland
2. Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
3. Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen, PSI, Switzerland
4. UPM Biomedicals, UPM-Kymmene Corporation, 00100 Helsinki, Finland
5. School of Phamacy, University of Eastern Finland, 70210 Kuopio, Finland